Yeah, I was going to say Goat Hill Tavern, which is actually in Costa Mesa (not quite Newport) on Newport Boulevard. It has an embarrassment of riches when it comes to draft brews and the place boasts about having the largest number of beers on tap (100+) than anywhere in Orange County. You'd be hard pressed not to find something there. Across the street from Goat Hill is Yardhouse, which is a chain that offers a substantial amount of beers, both domestic and imported.

Goat Hill is the only option. Yardhouse pads their selections with cheap domestics while Goat Hill's taps are primarily California and other Micros. Plus Goat Hill has sawdust on the floor and a kitchy dive vibe about it. If you need polished wood and pretense, Yardhouse would probably be a better fit.

While Goat Hill clearly has the best selection of beers (as the other posters have already noted), let's just say it leaves a little to be desired in terms of scenery. Since you are visiting, I'd recommend you hit up Mutt Lynch's in Newport Beach. It's right on the boardwalk and you can look out onto the beach as you chug a schooner. Sidenote: I just discovered on Sunday that they now have pitchers, which is the better way to go if you are drinking more than 1 schooner